Solenoid with hinged core



Oct. 26, 1954 R. w. BACHI 2,692,965

SOLENOID WITH HINGED CORE Filed May 16, 1952 2 Sheets-Sheet l JMMJI V REBEL-:2! BaUZTL $5 Oct. 26, 1954 R. w. BACHI 2,692,965

' SOLENOID WITH HINGED CORE Filed ,May 16, 19 52 2 Sheets-Sheet 2 JMW Faberi \A 530777.

Patented Oct. 26, 1954 STATES PATENT OFFICE Robert W. Eachi', Itasca, 111., assignor, by mesne assignments; to S'oreng Products Corporation, a-corporation of Delaware Applicatibn May 16; 1952,- SeriallNo. 288,263

9 Glaimsi (Cl. 317 197)- This invention relates to solenoids intended" primarily; although not exclusively; for alternating'current service; and like the related copendih'g application of! Robert Wi Bachi' and". Hardin Yl.Fisher; Serial No. 288,262, filed" May It, 1 952 refers moreparticularly to solenoids of 'thehinged core type.

In general it is the purpose of this invention to provide a solenoid" with a hinged armature movable. toward% the stator of the solenoid in response to energization of the winding and engageable with pole faces on the stator: at locations both inside and outside the winding to provide a completely closed magnetic circuit about the winding. This has the advantage of assuring maximum. pull or tracti've eifort" for the solenoid when it is energized, by: reason of the reduced reluctance of'the magnetic pathresulting from the elimination of air gaps in the magnetic circuit'throughithe core.

In conventional solenoids employing a plunger slida'ble end'wise in a coil, an air gap is usually provided somewhere in the magnetic circuit around the. coil so as to. enable the eilfects of residual. magnetism to be more readily overco'me. Aispring: acting on the plunger in opposition to the" magnetic forcetending to draw'the plunger-to" or hold" it in. its attracted position is usuallyemployedto overcome'the effects of residual" magnetism. following de-energization of the winding; 'Ihelargertheair gap in" the magnetic circuit the: easieritisf'or the residual spring toretract the plunger following de energi'zation' of thewindi'ng, but the" useof" a larger air gap inthem'agneticcircuit is alsoobjectionabIesince it results in the consumption of more current, requiresa larger winding and causes more heating: On the other" hand if the air gap is" too small an excessively strong spring force-must be" exerted on the plunger'inopposition t'othe force ofth'e" coil holding the plunger'inits attracted position with the result that the tractive effort of the plunger is seriously reduced;

It not only an object of this invention toprovidea solenoid with a hlnge'd armature 00-- operating; witha: stator to provide a completely closed magnetic circuit about the" winding when thesame'is energized; but it is afurther purpose of this invention to" mount: the stator for limited motion relativetothe coil so'that' a biasing force" can be directedagainst thestator, rather than the armature, to effect separation of the" coreparts upon de-energizationof the winding; In this manner, the biasing force utilized toovercomeresidual'magnetism does not act in oppositionto the magnetic" force tending to hold the" 2 load carrying core" element of the solenoid in its attractedposition. This concept of directing a biasing force against a movable core part of a solenoid, other than the armature thereof, to

effect separation of the core parts upon deenergization of the" solenoid is disclosed and claimed in the copendin'g application of Hardin Fishen, Serial No. 313,931, filed. October 9, 1952;, which application in turn is a continuation-in-p'art of two other applications of Hardin Y. Fisher, cop'ending therewith, Serial No. 236,299; filedJul'y' 12; 1951 an'd'SerialNo. 191,162; filedOctober 26, I950; and both now abandoned. More: specifically it is. the purpose of this invention to provide a solenoid of the character described with a pair. of. cooperating core elements both of which are mounted for pivotal motion toward and from one another. In one embodiment ofth'e" invention,. the armature may have an elongated substantially arcuate pole por tion thereon projecting into one end'of the Wind'- ing and movable into engagement with" a pole portion on the stator at theopposite end of the winding so that the magnetic circuit may ex" tend' through vthe pole portionsof the stator and armature centrally of the winding and may be completed through, other portions of the armature and stator lying alongside the exterior of the winding.

In another embodiment of this. invention the core parts can be said" to. comprise two substantially identical armature's' mounted to swing on separate pivots and constrained to swing towardone another iniunison in response to energization ofthe winding to bringcooperating pole faces on the armatures into intimate engagement with one another, both inside and outside of the coil. In this case, the hammer blow usually accompanying closure of the core parts largely dissipated and absorbedin the armatures themselves w'ithout'beingtr'ans'mitted to the supporting bracket upon. which the'solenoidis. mounted.

As comparedtothe conventional's'olenoid having a plunger slidable end'wise in" a coil and requi'ring a plunger guide to" constrain the plunger as well as'possiblei to endwise reciprocatory motion in" the coil, the solenoid" of this invention has'many important advantages; especially from the standpoint of lowercost' of manufacture and the utilization of" all of the power of the coil. Since the armature. is. pivotally supported on a supporting bracket holding the solenoid} the pole portion of the armature can travef inwardly and outwardly of theco'il with-great accuracy without the need' for the conventional plunger guide. This not only'reduces' the number of parts required, but eliminates such disadvantages attending the use of plunger guides as heating and other losses due to circulating currents in the guide and friction between the plunger and its guide. Friction alone between the plunger and its guide has been found to reduce the power of some conventional solenoids by as much as forty per cent (40%).

Another important advantage resulting from the use of pivoted or hinged core elements for solenoids of the character described results from the fact that the pole faces of the core elements can be brought into very accurate flat contact with one another in response to energization of the coil to thus eliminate the objectionable buzzing and chattering noises which very'frequently resulted in conventional solenoids when the plunger guide would not hold the plunger with its pole face in intimate engagement with the pole face on the stationary portion of the core; or such noises as occur when the load to which the plunger was attracted cause the plunger to tilt in its guide.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate several examples of the physical'embodiments of the invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

Figure l is a view partially in section and partially in elevation showinga solenoid embodying the principles of this invention;

Figure 2 is a View similar to Figure l but showing the positions of the core elements when the solenoid is energized;

Figure 3 is a sectional view taken through Figure 1 along the plane of line 3-3;

Figure 4 is a fragmentary view partially in section and partially in elevation taken along the plane of line 4-4 of Figure 1;

Fig-ure 5 is a View similar to Figure 1 but illustrating a modified embodiment of the invention;

Figure 6 is a view similar to Figure 5 but showing the core elements in attracted position;

Figure '7 is a cross sectional view taken through Figure 6 along the plane of line l-'l; and

Figure 8 is an elevational View of a solenoid like that of Figure 6, with portions thereof broken away, and illustratin a slightly modified embodiment thereof.

Referring now more particularly to the accompanying drawings in which like numerals designate like parts through the several views, the solenoid of this invention comprises a supporting bracket 5, preferably, but not necessarily, of U-shaped cross section, upon which an annularly wound coil 6 and a pair of cooperating core elements I and 8 are mounted. The winding 6 is accommodated in opposite identical openings in in the upright opposite legs H of the support ing bracket, with the hollow interior of the winding aligned with the space between the legs; and it is to be understood that the winding may be secured to the bracket in any suitable manner.

The core elements may be said to lie adjacent to the opposite ends of the winding 6, and in the embodiment of the invention disclosed in Figure 1 the core element 1 comprises a stator while the core element 8 provides an armature. Both core elements, of course, are received between the legs ll of the supporting bracket.

The stator I is comprised of a bank of fiat magnetically permeable laminations secured together by rivets and having a pole portion l2 overlying the adjacent end of the winding 6 and a lateral extension I3 projecting substantially radially beyond the periphery of the winding and terminating in a second pole ortion [4 alongside the exterior of the winding. The stator is preferably mounted on a pivot pin l6 having its ends received in the opposite legs I l of the supporting bracket and passing through an aperture I! in the stator adjacent to the pole portion l2 thereof to mount the stator for swinging motion about an axis crosswise but closely adjacent to the axis of the winding. The pole portion [2 of the stator may project slightly into the adjacent end of the winding, as shown, and both of its pole portions 12 and M are provided with fiat pole faces l9 and 20, respectively. Preferably, though not necessarily, the pole faces l9 and 2|! lie in a common plane substantially normal to the axis of the winding.

Swinging motion of the stator I on its pivot pin 16, in a clockwise direction to carry its lateral extension 13 away from the armature, is limited by the engagement of the lateral extension with a stop 2| on the supporting bracket struck up from the bight thereof. It will also be noted that the stator extension is provided with a tail piece 23 against which a compression spring 24 acts to yielding-1y resist counterclockwise swinging movement of the stator about its pivot pin away from the stop 2|. This spring reacts against a cross bar 25 extending between and secured to the legs I l of the supporting bracket, and it will be understood that the force of the spring is readily overcome by the magnetic attraction of the winding for the stator whenever the winding is energized so that the stator responds to energization of the winding against the bias of the spring 24.

The armature 8 is likewise comprised of a bank of fiat magnetically permeable laminations secured together by rivets in the customary manner, and it will be noted that the armature has a substantially U-shaped appearance when viewed in side elevation. One of the legs 21 of the armature projects into the end of the winding 6 remote from the stator pole portion, l2, and the opposite leg 28 of the stator lies ouside of the winding and projects along its exterior toward the lateral extension I3 of the stator to terminate closely adjacent to the pole face 2|! thereon.

The armature is also mounted for swinging motion on the supporting bracket. In the present case the armature is supported on a pivot pin 29 having its opposite ends received in the legs ll of the bracket and passing through an aperture 30 in the leg 28 of the armature near the extremity thereof. Hence the armature may swing about an axis parallel to the pivot axis of the stator but adjacent to one side of the winding and relatively closely adjacent to the pole face 20 on the stator. By reason of the fact that the armature is mounted for swinging motion about an axis alongside the winding, the leg 21 of the armature which constitutes one of its pole portions is made arcuate and concentric to the axis of the pin 29 so that it will swing freely into the winding in response to energization of the coil 6.

In the attracted position of the core elements seen in Figure 2 it will be noted that a flat pole face 3t on: the extremity of the arcuate pole por tion 21' has flat surface to surface engagement with the pole face i 9 of the stator just inside the lower end of the coil, while. asecond flat pole face. 32011!- the extremity of the armature leg 28 likewisehas flat surface to surface engagement with the pole fac 25 on the stator: extension. The-pole faces 31 and 3?; on the armature, like those of the stator, preferably also lie in.a commonplane parallel to the armature pivot axis and substantiallyperpendicular to the path of motion of the armature in its attraction stroke. In the attracted position: of the core elements, therefore, the pole faces 3! and 32 of the armature are flatwise intimately engaged with the pole faces 19 and 20, respectively, of the stator, tov provide a completely closed single path magnetic circuit aboutithe winding. 6.

It isimportantto. observe that the pole portion |2 of the stator in effect provides a stop engageableby the. pole portion 2?. of the armature to limit counterclockwise swinging motion thereof. in response to energization of the winding and to define the attracted position of the armature; while the extremity of the leg 253 of the armature provides in. effect av stop engageable by the extension. l3 of the stator to limit counterclockwise swinging motion of the stator in response to energization of the winding and to thereby define the attracted position ofthe stator.

Upon de-energization of the winding residual magnetism in the core is broken by the spring 2 1 which forces the extension 93 of the stator away from the adjacent extremity of the leg 28 of the armatur to thereby break the magnetic circuit around the coil at. a location exteriorly of the coil, allowing the armature to be retracted by the load to which it may be connected. Apertured ears 34 whichv may be formed integrally with armature laminations or alternatively on the opposite side plates of the bank. of laminations, as shown, provide for attachment of the armature to the load tov be actuated; and if th solenoid is to be used for'alternating current hold in service, shading rings. 35. may be imbedded either in the pole faces onthe armature, or on the pole faces I 9 and 23 of the stator as shown.

With the solenoid described maximum tractive effort is: assured by reason of the fact that the armature intimately engages the stator both inside and outside. the winding 6 to establish a completely closed single" path magnetic circuit about the winding. The pivotal mounting of the armature also eliminates the need for guides such as are conventionally employed with solenoids having reciprocatory plungcrs or armatures. In addition; the pivotal mounting of the armature assures perfectly flat and accurate seating of its pole: faces against those of the stator, thereby eliminating any tendency for the solenoid to produce loud buzzing and chattering noises in the attracted positions of the core elements.

Another highly important feature of the solenoid described is that despite the fact that there are. no airv gaps in the magnetic circuit about the winding in the. energized condition of the solenoid, the effects of residual magnetism ar readily overcome and the magnetic circuit broken exteriorly of the winding by the spring 2 2 without having the spring act in opposition to the magnetic: force holding the armature in its attracted position. The spring 2 acts only upon the stator and hence cannot resist motion of the armature toits attracted position.

. The solenoids illustrated. in Figures to 8, in-

6 clusive, are likewise provided with pivotally mounted core elements. In this case, however, the core elements 38 are nearly identicaland both may be considered armatures. are mounted on separate pivots 35 and 49 to swing about parallel axes crosswise of the axis of the winding 6, and both of the pivots are located at the same side of the coil as distinguished from the pivotal arrangement of the stator and armature disclosed in Figures 1 and 2. The armatures are generally U-shaped as viewed in side elevation and have one leg or pole portion 4i projecting into the winding from each end thereof and its other leg 42 exteriorly of the winding but adjacent to the side thereof. The pole portion or leg 4! of each armature is arcuately shaped and concentric to the pivot axis of its armature so as to travel freely in the coil 6, and the armatures are constrained to swing toward and from one another in unison by a connection therebetween which may comprise meshing gear teeth 44 formed either on the entire bank of laminations of alter natively on the opposite side plates of the laminations as shown.

With this arrangement it will be seen that in the retracted positions of the armatures defined by their engagement with cushioned stops 45 on the supporting bracket the extremities of their arcuate legs il project slightly into the opposite ends of the winding ii, and engage one another at substantially the center of the winding uponenergization of the coil.

The ll, of course, have fiat opposing pole thereon which engage flatwise with one another upon response of the armatures to energization of the coil; and the extremities of the legs are likewise provided with opposing fiat pole faces d3 arranged to engage one another in the attracted positions of the armatures, as seen in Figure 5, so as to establish a complete- 1y closed single path magnetic circuit about the winding. The pole faces on each armature also lie in a common plane parallel to its pivot'axis.

With the solenoid shown in Figure 5 to 8, inolusive, either armature may be connected to the load to be moved. For this purpose each armature is provided with apertured ears which may be located at any point on the armature distant from its pivot axis.

If desired the load to be moved by one of the arinatures may be connected to a lever 51 projecting downwardly through a slot 52 in the bight of the supporting bracket and formed as an extension of one of the side plates of the bank of laminae comprising the armature; or an independent lever may be secured to the pivot pin 52 if this pin is fixed to the armature as by key as to rotate with the armature. In this latter in stance the lever enables the solenoid to be used either as a pull or push type solenoid.

In the event the solenoid is to be used primarily for alternating current service under conditions where the coil will remain energized over a definite period of time as distinguished from momentary duty service where the coil is lo-energized practically as soon as the armatures reach their attracted positions, shading rings 55 are imbedded in the pole faces 5'? and it of one of the armatures in the conventional manner.

The solenoid illustrated Figures 5 to 8, inelusive, has the further advantage in that its armatures in traveling toward and from one another in unison collide with one another in a manner to relieve the supporting bracket of all shock incident to seating of the armatures.

The armatures Wherever residual magnetism in the completely closed magnetic circuit provided by the cooperating armatures in their attracted positions constitutes a serious problem, one of the armatures can be loosely pivotally supported on its pivot pin 39 for bodily motion of its pivoted end away from the pivoted end of the other armature, as indicated in Figure 8. For this purpose the opposite side plates of the bank of laminations comprising the left-hand armature 38 may have slightly elongated slots 56 formed therein to receive the pivot pin 39, the long axis of the slots substantially intersecting the axis of the other pivot pin 40. The slots 56, of course, limit separation of the pivoted ends of the two armatures to an extent such as to avoid the possibility of disruption of the toothed connection 44 therebetween. Figure 8 which shows this slightly modified embodiment of the solenoid illustrated in Figures and 6 indicates the extent of bodily movement permitted the lefthand armature on its pivot pin 39 under the influence of a tension spring 58 having one end connected to the armature as at 59 and its opposite end anchored to a cross pin 60 on the supporting bracket. In all other respects the solenoid of Figure 8 is like that shown in Figures 5, 6 and '7, and likewise features balanced inertia forces which are dissipated in the armatures themselves as they reach their attracted positions.

From the foregoing description taken together with the accompanying drawings it will be readily apparent to those skilled in the art that this invention provides a hinged core solenoid wherein a completely closed magnetic circuit is established through the hinged core members about the winding in the energization condition of the solenoid so as to assure maximum pull; and wherein residual magnetism in the core members may be readily overcome and the magnetic circuit about the coil broken exteriorly thereof by a force applied to one of the core members in a manner such that the biasing force does not oppose the force by which the armature is drawn to and held in its attracted position.

What I claim as my invention is:

1. In a solenoid: a supporting bracket; an annular winding carried by the supporting bracket; a laminated magnetically permeable stator having a pole portion overlying and substantially closing one end of the winding, and having a lateral extension projecting substantially radially to one side of the winding beyond the periphery thereof; means mounting the stator on the supporting bracket for limited pivotal motion about an axis adjacent to said end of the winding, perpendicular to the axis of the winding but closely adjacent thereto; a laminated magnetically permeable armature having a pole portion movable into the opposite end of the winding toward the stator pole portion to an attracted position in consequence of energization of the winding and having a lateral extension projecting substantially radially from the pole portion thereof to lie closely adjacent to the lateral extension of the stator at said side of the winding; a pivotal connection between the supporting bracket and said lateral extension of the armature mounting the armature for swinging motion about an axis parallel to the pivot axis of the stator so as to provide for swinging of the armature pole portion to and from its attracted position inside the winding; cooperating fiat pole faces on the pole portions of the armature and stator and on the lateral extensions thereof engageable fiatwise with one another in the attracted position of the armature whereby the armature and stator cooperate with one another to provide a completely closed magnetic circuit around the winding in the attracted position of the armature; means on the armature providing for connecting the same with a load to be moved; and resilient means reacting between the supporting bracket and the lateral extension of the stator to yieldingly bias the stator extension in a direction away from the armature extension and to separate said extensions upon deenergization of the winding to thereby effect breaking of said magnetic circuit exteriorly of the winding.

2. In a solenoid: a supporting bracket; an annular winding carried by the supporting bracket; a laminated magnetically permeable core for the winding including a stator and an armature and means mounting the same on the supporting bracket for motion relative thereto toward and from one another with the winding lying axially therebetween, said mounting means comprising separate pivot means for the stator and the armature constraining the same to swinging motion about parallel axes disposed crosswise of the axis of the winding, the stator axis lying near the adjacent end of the winding and close to the axis thereof, and the armature axis lying adjacent to one side of the winding at its exterior; cooperating pole portions on the stator and armature in line with the axis of the winding, the armature pole portion being movable into the winding toward the stator pole portion in response to energization of the winding, and the stator pole portion providing a stop interposed between the stator axis and the armature pole portion and engageable by the latter to define the attracted position thereof opposing pole faces on said pole portions of the stator and armature engageable with one another inside the winding when the winding is energized; and other opposing pole faces on the stator and the armature closely adjacent to the armature axis and engageable with one another exteriorly of the winding when the same is energized to provide a completely closed magnetic circuit about the winding, the portion of the armature engaged by said other pole face of the stator providing a stop directly alongside the armature axis to define the attracted position of the stator.

3. In a solenoid: a supporting member; an annular winding carried by said supporting member; a magnetically permeable stator having a pole portion thereon adjacent to one end of the winding in line with the axis thereof, and having an extension providing another pole portion on the stator lying adjacent to one side of the winding at its exterior; means mounting the stator on the supporting member for limited pivotal motion about an axis adjacent to said end of the winding, with the stator pivot axis perpendicular to the axis of the winding and closely adjacent thereto; a magnetically permeable armature adjacent to the other end of the winding, said armature having pole portions thereon opposite said pole portions of the stator; means mounting the armature on the supporting member for motion to and from an attracted position at which its pole portions engage those of the stator to provide a completely closed magnetic circuit around the winding; means on the armature providing for connecting the same with a load to be moved; and resilient means reacting between the supporting member and the stator to yieldingly bias said other pole portion thereon in a direction away from the opposite pole portion on the armature and to separate said last named pole portions upon deenergization of the winding, to thereby effect 9. breaking of said magnetic circuit at a zone exteriorly of the winding.

4. In a solenoid: a supporting member; an annular winding carried by the supporting member; cooperating core elements for said winding providing a stator and an armature, the stator having a pole portion directly adjacent to one end of the winding and the armature having a pole portion adjacent to one side of the winding at its exterior; a pivotal connection between each of said pole portions and the supporting member providing for swinging motion of said core elements about spaced parallel axes normal to the axis of the winding; a second pole portion on the stator engageable with said first designated pole portion or" the armature adjacent to the pivot axis thereof to define the attracted position of the stator; and a second pole portion on the armature movable into the end of the winding remote from the stator and engageable with said first desig- .i

nated pole portion of the stator adjacent to the pivot axis thereof to define the attracted position of the armature.

5. The solenoid set forth in claim 4 wherein the armature is provided with means for connecting the same with a load to be moved; and further characterized by the provision of yieldable means reacting between the supporting member and the stator for separating said second pole portion thereon from the first designated pole portion of the armature upon de-energization of the winding.

6. In a solenoid: a supporting member; an annular winding carried by the supporting member; a stator having a pole portion directly adjacent to one end of the winding and in line with the axis thereof, and having another pole portion at one side of the winding adjacent to the exterior thereof; an armature adapted to be connected to a load to be moved, said armature having a pole portion projecting into the other end of the winding and having another pole portion alongside the winding at its exterior and in opposing relationship to said other pole portion of the stator; means pivotally connecting said other pole portion of the armature to the supporting member to provide for swinging of its first designated pole portion into the winding to an attracted position engaging said first designated pole portion of the stator; means mounting the stator on said supporting member for limited motion of said other pole portion thereof toward and from an attracted position engaging said other pole portion of the armature adjacent to the pivot axis thereof; and

yieldable means reacting between the supporting member and the stator for effecting separation of said other pole portions of the stator and arma ture upon de-energization of the winding.

7. The solenoid set forth in claim 6 wherein said mounting means for the stator includes pivot means engaged by said other pole portion of the stator and providing for swinging of the first designated pole portion of the stator into the winding toward and from an attracted position engaging said first designated pole portion of the armature.

8. The solenoid set forth in claim 7 further characterized by the provision of meshing gear teeth on said other pole portions of the stator and the armature constraining the same to swing toward and from one another in unison.

9. In a solenoid: a supporting bracket; an annular winding carried by the supporting bracket; a pair of magnetically permeable core members embracing the winding and each having a pole portion projecting into one end of the winding and another pole portion extending around the adjacent end of the winding and projecting toward the other end of the winding at one side thereof; separate pivotal supports for said other pole portions providing for swinging of the core members, about spaced apart parallel axes perpendicular to the axis of the winding, toward and from attracted positions at which their first designated pole portions engage with one another inside the winding and their said other pole portions engage with one another exteriorly of the winding, the other pole portion of one of said core elements having a loose connection with its pivotal support providing for relative separating motion of said other pole portions along a line passing through the axes of said pivotal supports; yieldable means reacting between the supporting bracket and said one core element to effect relative separating motion between said other pole portions of the core elements upon drg-energization of the winding; and means on the other core element providing for connection of the same with a load to be moved.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 851,663 Jackson Apr. 30, 1907 2,322,574 Goldberg June 22, 1943 2,540,294 Schleicher Feb. 6, 1951 

